Adding a new roof vent (& cutting the hole for it)

handye9,

Thanks for the reply. I'm not having any luck getting any information from the manufacturer so I'm guessing I'm going to be on my own when doing this. I really don't mind cutting into the roof, I just know there's not a lot of room to fix it if I mess up cutting the hole. I like the idea of the 4 small holes and the X cut on the roof membrane. It's more like what the factory seems to do ... at least the ones that I've had to replace the original vents on.

I also need a day or so where I have the time and the weather is cooperating.

Thanks,

johnm1 wrote:
Hey all,

Has anyone ever added a new roof vent? I don't mean replacing an existing one ... I mean cutting the hole in the roof and putting one in where there wasn't one to begin with. Any tips or thoughts?

Thanks,

I did it on a previous trailer.

I emailed the manufacturer (Starcraft) and told them what I wanted to do. They actually sent me drawings that showed all the roof structures along with AC ducting. They couldn't send wiring diagram, because, wiring inside the ceiling is done while the unit is being built.

With the drawings and a stud finder, I was able to measure and mark the spot for the vent.

To prevent hitting any wiring, I used a spiral zip saw, set to cut slightly less than the depth of ceiling panel. Then finished the cut with a razor knife. Good thing cut was so carefull-- I did find wires, but, they were not cut. There was enough slack in the wires, to just move them out of the way.

I used a long (small diameter) drill bit. Drilled (at the four corners) up through the roof. Then, up on roof, cut (with razor) an "X" between the four drill holes. Fold the rubber roof material out of my way, connect the dots and cut hole from the top. Cut the hole with rounded corners. Fold rubber roof material back into the 14" hole and cut off excess hanging inside.

Install the vent (as directed) with butyl tape and caulking. Inside, install the trim ring. Done

Hmmm ... I never thought about making sure the corners were rounded or not but it makes sense to me. Thanks for the idea.

I can tell you this . DO NOT CUT A HARD 90* IN THE CORNERS!! Make sure you make about a 1" radius into the corners. It will prevent cracking. Most critical with a hard surface like fiberglass. Regardless please take my advice any roofing materials that take that kind of abuse will crack over time in the corners unless the are rounded.
Good luck

Old Duck - Yeah ... that would be really nice but I don't have any roof vents in the back of the RV.

I called the factory and, after telling me that the factory "doesn't recommend modifying the RV" (he was just covering his um ... back side) he suggested that I remove the ceiling panel to gain access to the area. Sounds like a PITA but I'll see what's involved and if it's too much then I'll go with the stud finder, cram my voltage tester up in the ceiling to see if there are any wires up there and hope for the best.

Just a random wild thought, assuming you have a vent already somewhere (other than a bathroom) could you add something like a Fan-tactic Vent to an existing vent location. I had one in our bedroom area, found out the vent in the living room had power near it so had one added. What a world of difference having a fan that pulls air in or pushes it out in both vents.

Boy wouldn't that be nice if it was already framed and I never even thought about a stud finder either ... and I have one! The AC ducts don't go that far back in the trailer so I'm good that way and I think all of the electric wires "shouldn't" be in the way???!?!??? Only one way to find out!

Thanks,

Have you ever seen any other of your trailer or other models of your brand with a vent in the area you want to put one?? The roof "might be" framed for one already.

Initially Jayco told me that our model (only came with one vent in bath) wasn't framed for a bedroom vent, but on inspection and using a good stud finder, found out it was framed in for a standard 16" vent. Only needed to mark and cut inside and then drill corner holes before going on the roof to finish. Did need to tap into a hot light wire for a fan (Vortex) in the vent. Wasn't a big job, but measure, check, measure, check (!!!) before cutting.

If it isn't framed, it's pretty easy to work from a rafter and add cross beams to support the inside flange of the vent. Also, if ducted a/c, you should be able to stay away from the ductwork, most I've seen don't go down the middle of the roof, usually to one side of center.

Dicor or a high dollar tape (Eternabond) for sealing to roof material.

Yes, no ducted a/c made it easier. Lots of wires up there that surprised me, so be carefull cutting. I started from the inside after finding where the rafters were. Good luck!

Ye be braver than I, while I am sure it could be done cleanly and leak free I consider my roof to have enough holes in it already :)